Centrum Semiovale. A, Color-coded DTI axial map at the level of the centrum semiovale, which is defined as the common central mass of white matter with an oval appearance in horizontal sections of the brain. From lateral to medial, the superior longitudinal fasciculus (anteroposterior orientation, green), corona radiata (craniocaudal orientation, blue), and cingulum (anteroposterior orientation, green), are displayed. The different ROIs (orange) selected for the tractographic reconstruction of the centrum semiovale are shown. B, Tractographic reconstruction of the superior longitudinal fasciculus (horizontal or frontoparietal segment) laterally, the cingulum medially, and the corona radiata between the superior longitudinal fasciculus and cingulum. Some commissural callosal fibers are shown crossing under the cingulum and radiating between the cingulum and the corona radiata. All these fasciculi form the complex white matter structure of the centrum semiovale. C, Superior view, fiber dissection of the centrum semiovale. The fibers of the corpus callosum cross to the opposite hemisphere under the cingulum. The superior longitudinal fasciculus forms the most lateral part of the centrum semiovale. The corona radiata is situated between the cingulum and superior longitudinal fasciculus, and is intermingled with the callosal radiations. The corona radiata and superior longitudinal fasciculus have been removed on the left side to expose the lateral ventricle, the caudate nucleus, and the thalamus. D, Coronal section at the level of the foramen of Monro on the right side, and at the level of the anterior commissure in the left side. The white matter extends from the cortex to the basal ganglia and ventricular system. The common central mass of white matter with an oval appearance in horizontal sections of the brain is termed the centrum semiovale. It is located above the lateral ventricles and is formed by the superior longitudinal fasciculus, corona radiata, cingulum, and callosal fibers. E, Coronal view of the tractographic reconstruction shown in B. The corona radiata is formed by the internal and external capsule fibers. Correlation with the anatomic specimen shown in D. (Images courtesy of E de Oliveira)